<?php
/**
*rsa 解密文件
*@author bigticket 
*@date 2013-05-27
*/
	define("RSA_MODULUS","38032694873872597017706018691719866742698253162663359093660336158668564631227968345286730670731156627688540608741126465826101066479454680163716848587232981380124722916764678368772229951258842553895208508785914186450065511494633882071412831965336635736214440227709792473266383828613935140904240702907659105207");

	define("RSA_PRIVIATE","27186270371826052186974035593247382787735338836089798433110847287953374016043724384381506941493078188141805000323911206412226884949222764043829462534212831822412968749514296497517864686538731033021082788256485931935856874159464548107771728871124951767625017797481184436733933745160935843036505123343433399441");


	define("RSA_PUBLIC","65537");

	define("RSA_KEYLEN","1024");

	//js传送解密
	function converDes($str){
		  if($str&&strlen($str)==256){
			 $encrypted=convert($str); 	
			 $decrypted = rsa_decrypt($encrypted,RSA_PRIVIATE,RSA_MODULUS,RSA_KEYLEN);
			 $str = $decrypted;
			 $encrypted = null;
			 $decrypted = null;
			 return strrev($str);
		 }
		 return $str;
	}

	/*
	 * PHP implementation of the RSA algorithm
	 * (C) Copyright 2004 Edsko de Vries, Ireland
	 *
	 * Licensed under the GNU Public License (GPL)
	 *
	 * This implementation has been verified against [3] 
	 * (tested Java/PHP interoperability).
	 *
	 * References:
	 * [1] "Applied Cryptography", Bruce Schneier, John Wiley & Sons, 1996
	 * [2] "Prime Number Hide-and-Seek", Brian Raiter, Muppetlabs (online)
	 * [3] "The Bouncy Castle Crypto Package", Legion of the Bouncy Castle,
	 *      (open source cryptography library for Java, online)
	 * [4] "PKCS #1: RSA Encryption Standard", RSA Laboratories Technical Note,
	 *      version 1.5, revised November 1, 1993
	 */

	/*
	 * Functions that are meant to be used by the user of this PHP module.
	 *
	 * Notes:
	 * - $key and $modulus should be numbers in (decimal) string format
	 * - $message is expected to be binary data
	 * - $keylength should be a multiple of 8, and should be in bits
	 * - For rsa_encrypt/rsa_sign, the length of $message should not exceed 
	 *   ($keylength / 8) - 11 (as mandated by [4]).
	 * - rsa_encrypt and rsa_sign will automatically add padding to the message. 
	 *   For rsa_encrypt, this padding will consist of random values; for rsa_sign,
	 *   padding will consist of the appropriate number of 0xFF values (see [4])
	 * - rsa_decrypt and rsa_verify will automatically remove message padding.
	 * - Blocks for decoding (rsa_decrypt, rsa_verify) should be exactly 
	 *   ($keylength / 8) bytes long.
	 * - rsa_encrypt and rsa_verify expect a public key; rsa_decrypt and rsa_sign
	 *   expect a private key.
	 */

	/**
	 * 于2010-11-12 1:06分于LONELY修改
	 */
	function rsa_encrypt($message, $public_key, $modulus, $keylength)
	{
		$padded = add_PKCS1_padding($message, true, $keylength / 8);
		$number = binary_to_number($padded);
		$encrypted = pow_mod($number, $public_key, $modulus);
		$result = number_to_binary($encrypted, $keylength / 8);
		
		return $result;
	}

	function rsa_decrypt($message, $private_key, $modulus, $keylength)
	{	
		$number = binary_to_number($message);
		$decrypted = pow_mod($number, $private_key, $modulus);
		$result = number_to_binary($decrypted, $keylength / 8);
		return remove_PKCS1_padding($result, $keylength / 8);
	}

	function rsa_sign($message, $private_key, $modulus, $keylength)
	{
		$padded = add_PKCS1_padding($message, false, $keylength / 8);
		$number = binary_to_number($padded);
		$signed = pow_mod($number, $private_key, $modulus);
		$result = number_to_binary($signed, $keylength / 8);

		return $result;
	}

	function rsa_verify($message, $public_key, $modulus, $keylength)
	{
		return rsa_decrypt($message, $public_key, $modulus, $keylength);
	}

	function rsa_kyp_verify($message, $public_key, $modulus, $keylength)
	{
		$number = binary_to_number($message);
		$decrypted = pow_mod($number, $public_key, $modulus);
		$result = number_to_binary($decrypted, $keylength / 8);

		return remove_KYP_padding($result, $keylength / 8);
	}

	/*
	 * Some constants
	 */

	define("BCCOMP_LARGER", 1);

	/*
	 * The actual implementation.
	 * Requires BCMath support in PHP (compile with --enable-bcmath)
	 */

	//--
	// Calculate (p ^ q) mod r 
	//
	// We need some trickery to [2]:
	//   (a) Avoid calculating (p ^ q) before (p ^ q) mod r, because for typical RSA
	//       applications, (p ^ q) is going to be _WAY_ too large.
	//       (I mean, __WAY__ too large - won't fit in your computer's memory.)
	//   (b) Still be reasonably efficient.
	//
	// We assume p, q and r are all positive, and that r is non-zero.
	//
	// Note that the more simple algorithm of multiplying $p by itself $q times, and
	// applying "mod $r" at every step is also valid, but is O($q), whereas this
	// algorithm is O(log $q). Big difference.
	//
	// As far as I can see, the algorithm I use is optimal; there is no redundancy
	// in the calculation of the partial results. 
	//--
	function pow_mod($p, $q, $r)
	{
		// Extract powers of 2 from $q
		$factors = array();
		$div = $q;
		$power_of_two = 0;
		while(bccomp($div, "0") == BCCOMP_LARGER)
		{
			$rem = bcmod($div, 2);
			$div = bcdiv($div, 2);
		
			if($rem) array_push($factors, $power_of_two);
			$power_of_two++;
		}

		// Calculate partial results for each factor, using each partial result as a
		// starting point for the next. This depends of the factors of two being
		// generated in increasing order.
		$partial_results = array();
		$part_res = $p;
		$idx = 0;
		foreach($factors as $factor)
		{
			while($idx < $factor)
			{
				$part_res = bcpow($part_res, "2");
				$part_res = bcmod($part_res, $r);

				$idx++;
			}
			
			array_push($partial_results, $part_res);
		}

		// Calculate final result
		$result = "1";
		foreach($partial_results as $part_res)
		{
			$result = bcmul($result, $part_res);
			$result = bcmod($result, $r);
		}

		return $result;
	}

	//--
	// Function to add padding to a decrypted string
	// We need to know if this is a private or a public key operation [4]
	//--
	function add_PKCS1_padding($data, $isPublicKey, $blocksize)
	{
		$pad_length = $blocksize - 3 - strlen($data);

		if($isPublicKey)
		{
			$block_type = "\x02";
		
			$padding = "";
			for($i = 0; $i < $pad_length; $i++)
			{
				$rnd = mt_rand(1, 255);
				$padding .= chr($rnd);
			}
		}
		else
		{
			$block_type = "\x01";
			$padding = str_repeat("\xFF", $pad_length);
		}
		
		return "\x00" . $block_type . $padding . "\x00" . $data;
	}

	//--
	// Remove padding from a decrypted string
	// See [4] for more details.
	//--
	function remove_PKCS1_padding($data, $blocksize)
	{
		//以下部分于原版的RSA有所不同,修复了原版的一个BUG
		//assert(strlen($data) == $blocksize);
		$data = substr($data, 1);

		// We cannot deal with block type 0
		if($data{0} == '\0')
			die("Block type 0 not implemented.");

		// Then the block type must be 1 or 2 
		//assert(($data{0} == "\x01") || ($data{0} == "\x02"));

	//	echo $data;
		// Remove the padding
		$i=1;
		while (1){
			$offset = strpos($data, "\0", $i);
			if(!$offset){
				$offset=$i;
				break;
			}
			$i=$offset+1;
		}
		//$offset = strpos($data, "\0", 100);
		return substr($data, $offset);
	}

	//--
	// Remove "kyp" padding
	// (Non standard)
	//--
	function remove_KYP_padding($data, $blocksize)
	{
		assert(strlen($data) == $blocksize);
		
		$offset = strpos($data, "\0");
		return substr($data, 0, $offset);
	}

	//--
	// Convert binary data to a decimal number
	//--
	function binary_to_number($data)
	{
		$base = "256";
		$radix = "1";
		$result = "0";

		for($i = strlen($data) - 1; $i >= 0; $i--)
		{
			$digit = ord($data{$i});
			$part_res = bcmul($digit, $radix);
			$result = bcadd($result, $part_res);
			$radix = bcmul($radix, $base);
		}

		return $result;
	}

	//--
	// Convert a number back into binary form
	//--
	function number_to_binary($number, $blocksize)
	{
		$base = "256";
		$result = "";

		$div = $number;
		while($div > 0)
		{
			$mod = bcmod($div, $base);
			$div = bcdiv($div, $base);
			
			$result = chr($mod) . $result;
		}

		return str_pad($result, $blocksize, "\x00", STR_PAD_LEFT);
	}


	/**
	 * 16 to 2
	 * @param unknown_type $hexString
	 * @return string|unknown
	 */
	  function convert($hexString) 
		{ 
				$hexLenght = strlen($hexString); 
				// only hex numbers is allowed 
				if ($hexLenght % 2 != 0 || preg_match("/[^\da-fA-F]/",$hexString)) return FALSE; 

				unset($binString); 
				for ($x = 1; $x <= $hexLenght/2; $x++) 
				{ 
						$binString .= chr(hexdec(substr($hexString,2 * $x - 2,2))); 
				} 

				return $binString; 
		} 
?>